Simultaneous desize-scour-bleach with activated hydrogen peroxide

ABSTRACT

This invention provides a combination desizing, scouring and bleaching process for greige textiles employing an alkaline hydrogen peroxide and peroxydiphosphate.

United States Patent 1191 Sitver et al.

[ Oct. 16, 1973 SIMULTANEOUS DESIZE-SCOUR-BLEACH WITH ACTIVATED HYDROGENPEROXIDE [75] Inventors: Leonard Allan Sitver; Robert Emil Yelin, bothof Willingboro, NJ.

52 u.s.c1 .Q 8/111, 8/138, 8/139 51 1m.c1 ..D0613/02 58 Field of Search8/111, 138,139

[56] References Cited UNITED STATES PATENTS 3,649,164 3/1972 Yellinet-al. 8/111 l/l972 Yellin et al. 8/111 Primary Examiner-Mayer WeinblattAttprneyNicholas De Benedictis et al.

[57] ABSTRACT This invention provides a combination desizing, scouringand bleaching process for greige textiles employing an alkaline hydrogenperoxide and peroxydiphosphate.

4 Claims, No Drawings SIMULTANEOUS DESIZE-SCOUR-BLEACH WITH ACTIVATEDHYDROGEN PEROXIDE DESCRIPTION OF THE PRIOR ART Textiles are usuallydesized, scoured, and bleached before they are dyed or subjected tosimilar finishing" processes such as process for impartingpermanentpress or stain-repellent properties. To obtain consistent, highquality results with commercial quantities of textiles the desizing,scouring and bleaching steps are usually performed separately.

Desizing consists of removing any sizing compound that may have beenadded during weaving. Scouring removes fats, oils or waxes that may beon the fabrics and which interfere with uniform dyeing and bleaching.After desizing and scouring the fabric is bleached to whiten the fabricand make it more receptive to finishing chemicals. Various tests areperformed on the fabric to determine the effectiveness of the desizing,scouring and bleaching operations and the receptiveness of the treatedfabric to post-bleaching processes. The properties of the fabricnormally tested are the reflectance (whiteness), average dropabsorbency, the drop absorbency range, percent water extractables,percent enzyme extractables and percent fats, oils and waxes.

Fabrics having acceptable values for the above properties have beenobtained by separate desizing, scouring and bleaching treatments. Forexample, fabrics are desized with enzymes, hot caustic, alkalineperoxygens or bromine. Following this desizing step the fabric issecured with an alkali to remove the fats, oils and waxes as well asother impurities that the desizing process fails to remove. Good dropabsorbency properties are usually obtained by this scouring process.Subsequently, the fabric is bleached to obtain high whiteness(reflectivity) employing bleaching chemicals such as hydrogen peroxide.

Substantial commercial advantages are obtainable by a process whichwould combine the desizing, scouring and bleaching operations into onecontinuous process; however, such a commercially feasible single-stagebleaching" process has not been developed that is capable ofcontinuously. producing high quality products.

A significant improvement towards development of a single-stagebleaching process is described in U.S. Patent 3,026,l66, issued toGerald Gallagher et al. That patent describes a cold bleaching processusing a hydrogen peroxide-dipersulfate bleaching solution which issometimes referred to herein as the Gallagher pro.- cess. The Gallagherprocess is carried out at about room temperature for a prolonged period,that is from 6 to 24 hours. Although the Gallagher process bleaches andimproves the drop absorbency of fabrics, it is not readily adaptable tocontinuous operation but is practiced batch-wise because of the longretention time required for processing. A significant disadvantage ofthe Gallagher process is that a commercially acceptable product can onlybe consistently obtained at cold bleaching temperatures, that is fromabout 50 to 120F., which temperatures require substantial bleachingtimes of from 6 to 24 hours.

' U.S. Pat. No. 3,148,019, issued to Gallagher et al. performed both ahigh temperature scouring step with an alkali and then a bleaching stepwith alkaline hydrogen peroxide in a single piece of equipment, but didnot combine desizing, scouring and bleaching into a singlestep.

SUMMARY OF THE INVENTION We have invented a combination desizing,scouring and bleaching process which is capable of continuous productionof consistently high quality bleached textiles that are very suitablefor post-bleaching finishing treatments such as dyeing, stain repellingand permanent-press treatments. This process comprises dampening thefibers with an aqueous alkaline hydrogen peroxide solution containing aperoxydiphosphate and heating the dampened fibers to a processingtemperature of 180F. to 275F., and preferably about 212F., for betweenl.0 and 90 minutes whereby a high quality desized, scoured and bleachedfiber is obtained. The quality of the desized, scoured and bleachedproduct can be improved by adding to the aqueous alkaline hydrogenperoxide-peroxydiphosphate solution an organic hydrocarbon solvent, asurfactant, a stabilizer, and combinations thereof.

DETAILED DESCRIPTlON OF THE INVENTION This invention provides acombination desizing, scouring and bleaching process for textilescomprising dampening the textile fibers with a bleach containing asessential ingredients an aqueous alkaline hydrogen peroxide and aperoxydiphosphate and heating the dampened fibers to a processingtemperature of about 180F. to 275F. for between 1.0 and 90 minutes.

Both synthetic and cotten fibers and combinations thereof can bedesized, scoured and bleached by the process of this invention. Thequality of the desized, scoured and bleached fabric can be improved bycombining with the alkaline hydrogen peroxideperoxydiphosphate solution,a stabilizer such as sodium silicate, an organic hydrocarbon solventsuch as Varsol, or other similar petroleum distillate fraction solventsand a surface active agent of the type normally used in bleachsolutions, preferably either an ionic or nonionic surfactant.

The processing temperature preferably is about 2l2F., and normally isobtained by contacting the dampened fabric with steam at ambientpressure. However, temperatures somewhat lower than 2l2F., e.g. about180F., can be employed although the processing time increases as thetemperature decreases below 212F. Temperatures above 212F. can beobtained by performing the process in a pressure type bleaching vesselin which temperatures as high as about 275F.

' can be obtained. At these elevated temperatures above 212F. processingtime is decreased and good results obtained in as little as one minute.

The process is performed by dampening the textile fibers with the bleachsolution so that the dampened fibers contain about 50 to 150 parts byweight of bleach solution for each parts by weight of fiber. Thedampening of the fibers is carried out by conventional means, forexample, they can be immersed in the bleaching bath, removed from thebath and squeezed to remove excess bleach. Other suitable means will beapparent to one skilled in fiber-treating.

The bleaching solution is an aqueous solution containing as essentialingredients (a) between 0.5% and 5.0% hydrogen peroxide (based on 50%hydrogen peroxide solution) and/or amounts of other peroxygens, e.g.,perborates or percarbonates, that yield hydrogen peroxide in solutionsuch that the hydrogen peroxide value is within the required percentagesof 0.5% and 5%, (b) between 0.1% and 1.5% by weight of a watersolubleperoxydiphosphate such as potassium peroxydiphosphate, sodiumperoxydiphosphate or similar water-soluble salts of peroxydiphosphoricacid, and (c) between 0.1% and 2.0% of an alkali such as sodiumhydroxide, preferably about 0.8% to 0.9%.

The effects of the bleaching solution are improved by adding one or moreof the following:

1. a stabilizing amount of a silicate such as sodium silicate.

2. at least 0.1% of an organic hydrocarbon solvent such as Varsol orsimilar petroleum distillate fraction solvents,

3. at least about 0.005% and preferably about 0.1% of a wetting agent orsurface active agent such as Triton X-100 or other nonionic or anionicwetting agents such as an alkyl aryl sodium sulfonate or an alkyl arylpolyether alcohol.

The preferred amount of solvent is between 0.8% to 1.0% because greateramounts do not produce sufficient improvement-in relation to the addedcost and increased disposal problem. The preferred characteristics ofthe petroleum distillate fraction solvent are, Aniline Point between100F. and 150F., Kairi-Butanol Value between 32 and 47, a SolubilityParameter between 7.5 and 8.1, Flash Point, TCC between 100F. and 145F.,Initial Boiling Point greater than 3001F. and Final Boiling Point lessthan 410F. A typical composition of such a solvent is (Vol. Aromaticsbetween and 33%, Olefins less than 1%, Naphthenes between 26% and 43%,Paraffins between 32% and 60% and a Bromine Number between 0.08 and0.28.

Additives for adjusting or buffering the pH of this solution are notrequired as long as the essential peroxygen ingredients are containedwithin their desired concentrations.

The following examples are given by way of illustration of the presentinvention only and are not intended to limit the scope thereof. intesting the properties of the cloth both before and after treatment, thefollowing procedures were used.

a. Non-cotton content was determined using AATCC tentative test method97-1960 with the results obtained as percent enzyme extractables,percent water extractables and percent fats, oils and waxes.

b. Reflectance values were determined with a Hunter lab reflectometerfor whiteness, Model D-40 using a blue filter and employing AATCC testmethod c. Absorbency was determined using AATCC test method 79-1968.

In all of the examples the greige textile fabric treated was a 100%cotton broadcloth, 2.6 yards per pound and 66 X 66 threads per inch.Before treatment the fabric contained 6.2% water extractables, 5.2%enzyme extractables and 0.82% fats, oils and waxes. Allpercentagesherein are weight percentages unless otherwise stated and percentages ofhydrogen peroxide stated herein are weight percentages of 50% hydrogenperoxide solution. I

Example A (Comparative) A cotton broadcloth sample was dampened to 100%saturation with an aqueous solution containing 3% hydrogen peroxide (50%solution), 2% sodium silicate 4 (42Be), 0.8% sodium hydroxide, 0.25%petroleum distillate fraction solvent, and 0.1% nonionic wetting agent.The dampened fabric was heated to 212F. with steam for 90 minutes andthen washed. The fabric was then analyzed and had the propertiesreported in Table 1, column A.

Examples B, C, 1, ll and Ill The procedure of Example A was repeatedwith comparative bleaching solutions 13 and C having the compositionreported in Table I and with bleaching solutions 1, 11 and 111 havingcomposition within the scope of this invention as reported in Table 11.The effects of each bleach solution upon the fabrics are reported inTable I. A comparison of the results reported in Table 1 substantiatesthe consistently high quality results obtained with the process of thisinvention.

The best mode contemplated for practicing this invention is by employingthe solution composition, process time and temperature used in Example111.

Within the best mode contemplated for practicing this inventionthe-solution composition can vary to some extent from the amounts usedin Example 111, that is, the preferred composition ranges are:

a. hydrogen peroxide, between 2.5% and 3.5%,

b. alkali, between 0.8% and 0.9%,

c. a stablizing amount of silicate, usually about 2% sodium silicate,

d. peroxydiphosphate, between 0.2% and 0.5%,

e. solvent, between 0.8% and 1.0%, and

f. wetting agent, about 1.0%.

Pursuant to the requirements of the patent statutes, the principle ofthis invention has been explained and exemplified in a manner so that itcan be readily practiced by those skilled in the art, suchexemplification including what is considered to represent the bestembodiment of the invention. However, it should be clearly understoodthat, within the scope of the appended claims, the invention may bepracticed by those skilled in the art, and having the benefit of thisdisclosure, otherwise than as specifically described and exemplifiedherein.

TABLE I Example A B C I II III Composition:

Hydrogen peroxide....... 3.0 3.0 3.0 3.0 3.0 3.0 Sodium hydroxide 0. 0.80 0 0. 90 0. 90 0. 80 Sodium silicate (42 B.).. 2.0 2.0 2.0 2.0 2.0 2.0Peroxydiphosphatc 0.30 0.30 0.30 \arsol 0. 25 0. 25 0. 25 0. 25 0. 25Triton X- 0.10 0.10 0.10 0.10 0.10 0.10 Results:

Percent reflectance 84. 2 84. 2 84. 5 85. 3 85. 2 85.8 Drop absorbency52. 3 28. 3 2. 7 8. 5 1. 2 Percent extractables:

Water .63 .42 Enzyme 51 36 Fats, oils and waxes .24

"Cloth samples not tested for percent extractables or fats, oils andwaxes.

We claim: 11. A combination desizing, scouring and bleaching process forgreige textile fibers comprising dampening greige unbleached textilefibers which contain all of the sizing compound and fats, oils or waxesoriginally present and added in processing with a solution consistingessentially of water,between 0.5% and 5.0% hydrogen peroxide added assuch or derived in solution from other peroxygens, between 0.1% and 2%of an alkali and between 0.1% and 1.5% of a water-solubleperoxydiphosphate, heating the dampened fibers to about 180F. to about275F. for between 1.0 and 90.0 minutes, and washing the fibers to removethe solubilized sizing and oils, fats or waxes.

2. The process of claim 1 in which the solution conbetween 0.2% and 0.8%of the peroxydiphosphate and between 2.5% and 3.5% hydrogen peroxide.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO.3,765,83 r DATED I October 16, 1973 INVENTOR(S) 1 Leonard Allan Sitverand Robert Emil Yelin It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 1, line #7, "single-stage bleaching" should be in quotes.

Column 6, line 1, "paraffinicnaphthenic" should read--paraffinic-naphthenic--.

Signed and Scaled this twenty-eight D ay Of October 1 975 [SEAL] Arrest:

RUTH C. MASON C. MARSHALL DANN Arresting Office) Commissioner of Parentsand Trademarks UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTIONPATENT NO. 3, 765 83 DA ED October 16, 1973 INVENTOR(S) 1 Leonard AllanSitver and Robert Emil Yelin It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 1, line i'i, "single-stage bleaching" should be in quotes.

Column 6, line 1, "par'affinicnaphthenic" should read--paraffinic-naphthenic--.

Signed and Scaled this twen ty-eight D ay Of October 1 975 [SEAL] A!test:

RUTH C. MASON C. MARSHALL DANN Arresting Officer Commissioner ojPatentsand Trademarks

2. The process of claim 1 in which the solution contains at least 0.1%of a paraffinicnaphthenic nonolefinic petroleum distillate fractionsolvent.
 3. The process of claim 1 in which the solution contains astabilizing amount of a water-soluble silicate and about 0.1% of anonionic or anionic wetting agent.
 4. The process of claim 1 in whichthe solution contains between 0.8% and 1.0% of the petroleum solvent,between 0.2% and 0.8% of the peroxydiphosphate and between 2.5% and 3.5%hydrogen peroxide.